A group of U2 fans claim a ticket broker ruined their “Beautiful Day” by doubling the price of their already-paid-for tickets for tomorrow night’s Madison Square Garden concert.

Debbie O’Keeffe, a 25-year-old secretary from Yonkers, said she and 17 friends pooled their money in January to buy tickets to see the Grammy-winning Irish rock band.

Tickets for U2’s two Madison Square Garden shows – part of a 33-city North American tour – were sold out within days of going on sale Jan. 22.

O’Keeffe said she paid Spotlight Entertainment, a Stamford, Conn., ticket broker, $164 for each ticket – which had a face value of $85.

“I paid for them with my credit card, and they said they would mail them to me,” O’Keeffe told The Post. “I wasn’t worried. I was willing to wait a while to get the tickets, since it was only January.”

O’Keeffe said she got nervous about a month ago when she hadn’t yet received the tickets.

“All they kept saying was, ‘Don’t worry. We’ll be mailing them in a few weeks.’ So all I did was wait and wait. They even called me this week to confirm my address. I thought I had no reason to worry.”

O’Keeffe said that when she didn’t get the tickets this week, she decided to call the ticket agency again, only to hear from a man named John that he wanted another $286 per ticket because they didn’t have the ducats she had purchased five months ago.

“This is ridiculous. I want the tickets I paid for at the price I paid,” she said. “My co-workers and I were very excited about seeing them and now it seems that we’re not going anymore.”

Spotlight Entertainment did not return phone calls seeking comment.

O’Keeffe said she was offered a refund yesterday, but still feels she was ripped off and denied a chance to see her beloved band.

“I can’t believe they can get away with this,” she said. “I bet they pull off scams like this all the time just to make more money. This time, they ruined my chance to see my favorite band.”

Buyers should beware when they deal with ticket brokers, says New York City Consumer Affairs Commissioner Jane Hoffman.

“Always use a licensed broker and pay with a credit card,” she advised.